1. Technical Field
This invention relates to a writing implement, and, more specifically, to an improved collapsible pen.
2. Background Art
Pens, especially ballpoint pens, have long been instrumental to everyday life. They are crucial to the performance of any task that requires a person to write things by hand, especially when this writing should be of a permanent nature. Pens are used, for example, for signing legal documents, taking notes in meetings and lectures, recording medical notes in patient records and writing letters. The typical person cannot imagine life without this simple writing implement.
Since pens are so popular and widely used, pens are often inscribed with advertising material, such as a company""s logo or trademark. They are often given away at promotional events and set out for customers to use. This method of advertising is relatively inexpensive and provides wide coverage because a pen is often used by more than one person, or is invariably lost and found by another person.
Since pens are so useful, they are often carried with people where ever they go. This practice, does, however, have some drawbacks. For example, the typical pen is six or seven inches long, which often makes it difficult to comfortably carry in one""s pocket. Pens of the typical length so carried will often jab the person carrying the pen. This is particularly true when a person is quite active, such as when performing strenuous physical exercise such as running, or working in the field.
Another disadvantage of the typical pen is that many pens require a cap to prevent them from inadvertently writing on unintended objects or leaking on one""s clothing. These pen caps are often lost or separated from the pen, thus making the pen difficult to transport without the risk of ink leaking on one""s belongings.
Yet another disadvantage related to prior writing implement designs, is that they are sometimes held together with screws. The screws tend to loosen with use over time, and the pen then falls apart, rendering it useless.
To prevent the common problems and disadvantages of the current pen configurations, an improved pen is required. This improved pen should be small enough to easily transport without injury. Such an improved writing implement would provide major advancements in functionality and practicality over the present technology. It would also prevent the writing instrument""s inadvertent marking or writing on unintended objects without the need for an unattached cap. Additionally, such a writing implement should be held together with other than screws to avoid the aforementioned problem of the screw loosening.
The present invention overcomes the common problems and disadvantages of prior writing implements by a pen that is expandable and contractible, and is small enough to be easily carried in any typical pocket. The design of the pen protects against inadvertent markings, making it unnecessary for it to have a detached pen cap. Furthermore, the pen of the present invention also incorporates no screws, making it immune to screw loosening problems.
The pop up pen of the present invention includes a pump handle with a curved or xe2x80x9chookedxe2x80x9d end, an outer sleeve, an inner pen casing, a spring, a pen cartridge and a connector, which in one embodiment is U-shaped. The inner casing has two portions, that are joinable by matching threads.
When the pen is assembled, a protrusion on the pump handle, which has a hole therein, is lined up with two protrusions on the outer sleeve, which also each have holes, so that all of these holes are coaxial and the flat head at the hooked end of the pump handle engages a slot at the end of the pen""s inner casing. The connector is then threaded through the holes such that the inner casing is held within the outer sleeve by the hooked end of the pump handle and the U-shaped connector. Before so assembling the pen, the spring is installed within the outer sleeve so that one edge of it rests on a ridge in the interior of the outer sleeve. The assembled inner casing, with the pen cartridge installed in it by inserting it within the inner casing portions and screwing them together, is then installed. Ridges on the outer surface of the inner casing and the interior of the outer sleeve capture the spring between them.
The pen, so assembled, can be extended and contracted to expose and conceal the writing tip of the pen cartridge at the end of the inner casing.
When the pen is in the contracted position, the flat head at the hooked end of the pump handle is engaged in the slot at the end of the inner casing and the length of the pump handle is generally parallel to the outer sleeve. In this position, the spring is fully extended and the writing tip is retracted so that it lies within the outer sleeve.
By grasping the pump handle at the end furthest away from its circular head and pulling it away from the outer sleeve, the circular head of the pump handle slides in the slot of the inner casing, acting as a cam, and extends through a slot of the outer sleeve. The inner casing, acting as a cam follower, slides forward and extends from the outer sleeve, exposing the writing tip of the pen cartridge. The spring is compressed between the ridge in the outer sleeve and the ridge on the inner casing. The pen in this position is ready to be used as a writing implement.
To retract the pen, the end of the pump handle is pivoted back toward the outer sleeve. The spring decompresses and the inner casing is retracted into the outer sleeve. In this retracted position the writing tip of the pen cartridge is within the outer sleeve and in this position the pen will not inadvertently mark on anything.
In an alternate embodiment of the pen of the present invention, the components of the pen are joined by a ring connector, vice a U-connector that is threaded through the holes of the protrusions.
The pen of the present invention is advantageous in that it is small enough to fit in one""s pocket, especially when it is in its retracted position. It also does not require a separate pen cap to prevent it from inadvertently marking on anything. Since no screws are used to put together the pen, screw loosening problems are avoided. Furthermore, the outer shell can easily be imprinted with a company name, logo or slogan by conventional methods, so the pen can readily serve as an advertising vehicle.
In addition to the just described benefits, other objectives and advantages of the present invention will become apparent from the detailed description which follows hereinafter when taken in conjunction with the drawing figures which accompany it.